This relates generally to testing wireless electronic devices and, more particularly, to testing multiple wireless electronic devices placed in a test chamber.
Wireless electronic devices typically include transceiver circuitry, antenna circuitry, and other radio-frequency circuitry that provide wireless communications capabilities. During testing, wireless electronic devices under test (DUTs) can exhibit different performance levels. For example, each wireless DUT in a group of DUTs can exhibit its own output power level, gain, frequency response, efficiency, linearity, dynamic range, downlink sensitivity, etc.
The performance of a wireless DUT can be measured using a radio-frequency (RF) test station. A radio-frequency test station typically includes a test host, a tester (i.e., a signal generator), and a test chamber. The signal generator is connected to the test host. Connected in this way, the test host configures the signal generator to transmit downlink radio-frequency signals during test operations.
In conventional radio-frequency test arrangements, a single wireless DUT having, for example, a wireless local area network (WLAN) transceiver is placed into the test chamber. The DUT is connected to the test host using a radio-frequency cable or coupled through a wireless waveguide or antenna system. A protocol-compliant data link connection is established between the signal generator and the DUT (i.e., radio-frequency signals are conveyed between the signal generator and the WLAN transceiver over an authenticated data link).
The test host can, as an example, be used to direct the signal generator to wirelessly transmit eight different types of test packets, each of which is encoded using a respective modulation scheme. Each time the DUT successfully receives a test packet, the DUT responds by sending an acknowledgement signal back to the signal generator.
A power detector unit coupled to the signal generator may be used to keep track of the number of acknowledgment signals that the signal generator receives from the DUT. The power detector unit may rely on externally supplied information to separately calculate the packet error rate for each of the eight different modulation schemes under test.
Downlink sensitivity is performed by lowering the output power level at which the test packets are being transmitted and monitoring the corresponding packet error rates using the power detector unit. Downlink sensitivity testing performed using the power detector unit may be costly.
Once the downlink sensitivity value has been determined for each of the modulation schemes, the DUT is disconnected from the test host (i.e., by unplugging the radio-frequency cable from the DUT) and is removed from the test chamber. To test a new DUT, the new DUT is connected to the test host (i.e., by plugging the radio-frequency cable into a corresponding mating connector in the new DUT) and is placed into the test chamber.
Wireless testing using this conventional approach may be inefficient, because the process of connecting a DUT to the test host, placing the DUT in the test chamber, testing the DUT, removing the DUT from the test chamber, and disconnecting the DUT from the test host one DUT at a time is time-consuming. Moreover, protocol-based testing allows testing of only a single DUT and requires more tedious measurement processes. Protocol-compliant testing also has a tendency to drop connections between the DUT and tester when the output power falls below the DUT's downlink sensitivity. Re-establishing the protocol compliant connection in order to complete testing can add significant time and cost to the test process.
It would therefore be desirable to be able to provide improved ways of performing sensitivity testing across multiple modulation schemes.